Vulnerability · Published Aug 27, 2026 · Assigned by WatchGuard
CVE-2026-81851Fireware OS Heap-Based Buffer Overflow in iked Allows Denial of Service
Medium 6.9
In plain English
A medium-severity heap buffer overflow in Fireware OS from WatchGuard. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).
Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.4%top 64.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A heap-based buffer overflow vulnerability in Fireware OS's iked process allows an authenticated administrator to crash the IKE daemon (iked), resulting in a denial of service, by saving a specially crafted configuration.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| WatchGuard | Fireware OS | 2025.0 – before 2026.2.112.0 – before 12.12.1 |
| WatchGuard | Fireware OS | 12.0 – before 12.11.9 |
| WatchGuard | Fireware OS | 12.0 – before 12.5.18 |
Weakness: CWE-122, CWE-1284 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://psirt.watchguard.com/CVE-2026-81851 vendor-advisory